Return-flue boiler.



No. 739.900. PATE-NTBD SEPT. 29, 1903. D. I'. MURPHY. RETURN FLUE'BOIL-ER.

'APPLIUATION FILED AUG. 4, 1902.

N0 MODEL.

VIO

UMF-1Dm STATES,

Patented September 29,

@PATENT OFFICE.

RETU R'N-LUIEBOILER.

SPECIFICATION forming part gf Letters Patent Ive. 799,990, dated september 29, 1903.

Appuattiontiea August 4, 1902.

Minnesota, have invented certain new and useful Improvements in Return-Flue Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to makek and use the same. Y.

My invention has for its object to improve the construction and operation of return-tlue boilers; and to this end it consists of the novel devices and combinations' of devices hereinafter described, and deined'in the claim.

The invention in its preferred form is illustrated in the accompanying drawings. Therein like characters indicate like parts throughout the several views. Y

Figure 1 is a vertical longitudinal section taken centrally through a boiler constructed in accordance with my invention; and Fig. 2 is an end elevation, with some parts broken away and others sectioned, of the boiler illustrated in Fig. 1.

Of the parts of the boiler which correspond `to the ordinary or old constructions the'numeral 1 indicates the main shell or body of the boiler; 2, the dome; f3, the main flue; 4f, the return-fines; 5, the outer flue-sheet, and 6 the steam-pipe. v

The parts now to be described relate to my improvements.

The numeral 7 indicates the head, and the numeral 8 the approximately cylindrical portion, of-a removable supplemental boiler-section, 'rigidly secured to and within which is aV smoke-box1 9.A This smoke-box 9 is shown as attened on top, asindicated at 10, and it is provided with a` projecting annular end section 1l, which is adapted to telescope over the outer end of the main boiler 1 and to be rigidly but detachably secured thereto, as-

shown, by means of a` plurality of. machinescrews 12, that engage directly in an annular band 13, directly and rigidly secured upon It will be noted that a vertically-extended section 14 connects the attened portion 10 of the smokebox 9with the upper portion of the annular extension 11, and it will be further noted that Serial No. 119,222. (No model.)

vtheginner edge of the supplemental section S is contracted at 15, so as to vjoin the said ex- ,tension or liange`11, to which it is secured witha steam-tight joint by rivets 16. Long' bolts 17 connect the flattened portion l0 of the smoke-box with the top of the supplemental section 8, while short bolts 18 connect the heads of the said smoke-box andY supplemental boiler-section. A small arlnhole or passage 19 opens through the headsof the said sections or parts 9 and 7, this hole being normally closed by a door o r c`overrr20.- A steam-conveying pipe 2l opens fromthe main -boiler 1'into the supplemental boiler-section 7 8, and likewise the water-conveying pipe 22 opens from the said boiler 1 into the said supplemental boiler-section. In order to carry out my scheme of making the supplementalboilersectionreadily detachable, the said pipes 21 and 22 are formed in sections, the sections of Vthesame. being connected, respectively, by

union-joints`23 and 24. In the drawings the pipe 2l is shown at the extreme top of the boiler and the pipe 22 at the eXtreme lower portion of the same. This has been done for the purpose of clearness ot' illustration, while, as a matter of fact, itis probable that in actual construction the said pipes would be located to one side or the other ofa vertical line drawn through the center of the boiler, this being necessary in many instances to give clearance for other partis of the engine.

It would of course in all cases be necessary that the steam-pipe 2l have both ends located above and the water-pipe 22 have both ends located below the level orA possible levels of f the column of water z, for otherwise proper lues the upper wall of the smoke-box is fiattened, so that it stands below the water-level. In virtue of this construction no fines are cut At a point above the uppermost ICC out by the application of the water-jacketed smoke-box; but, on the contrary, all that surface of the flue-sheet to which it is possible to apply ues or to which iues are ordinarily applied is left exposed to the interior of the said water-jacketed smoke-box.

With my improvement the smoke-box is \vaterjacketed,so that any and all heat which is' radiated through and from the same is caused to heat the surrounding Water, transforming the same into steam, and thereby preventing waste of heat. In this manner the supplemental boiler-section effects an economy in the use of fuel and increases the capacity of the boiler.

When it is desired to retube the returnfiues4,thesocalled supplemental boiler-section may be readily removed simply by lirst removing the screw-bolts 12 and disconnect ing the sections of the pipes 2l and 22 by means of the unions 23 and 24.

It Will of course be understood that I do not limit myself to the specified construction illustrated; but, on the contrary, my invention is capable of many modifications. The 'lues can readily be cleaned from either end of the boiler.

What I claim, and desire to secure by Letters Patent of the United States, is as follows:

In a returnflue boiler, a water-jacketed smoke-box, the peripheral surface of which projects radially outward beyond the adjoining cylindrical walls of the boiler, and the inner walls of which yfire-box follow approximately the cross-section of the boiler, up to a point above the flues, at which point it is flattened, substantially as described.

In testimony'whereof I affix my signature in presence of two witnesses.

DANIEL F. MURPHY.

Witnesses:

M. J. MCDONNELL, CHAs. J. LANE. 

